I have recently noticed a lot of bounced emails, especially to G-Mail accounts.. Gmail has decided to not accept email from domains that do not have PTR addresses (which is the ability to look at 23.30.204.236 and have it reply www.kpslashhaven.net)... Comcast does not let me set PTR addresses as they do it themselves the PTR address for my IP ends up being 23-30-204-236-static.hfc.comcast.net and they won't let me change it. As such some mail servers, particularly Google, will not accept email from the kp/ domain. I haven't given up finding a solution, but that's the state of it at present.